Fluid proportioning pump



Feb 1960 J. x. HOGAN 2,924,178

' FLUID PROPORTIONING PUMP Filed Jan. 28, 1955 5 Shets-Sheet 1 INVENTOR ATTORNEY" Feb. 9, 1960 J. x. HOGAN 2,924,178

1 FLUID PROPORTIONING PUMP Filed Jan. 28, 1955 5 Sheets-Sheet .2

( 9e INVENTOR (/Ol/N X. 5 00? ATTORNEYS" Feb; 9, 1960 Filed Jan. 28, 1955 J. x. HOGAN FLUID PROPORTIONING PUMP l l I -J 5 Sheets-Sheet 3 INVENTOR JOHN X //0G I/V BY 5% ywflw ATTORNEY" J. x. HOGAN 2,924,178

FLUID PROPORTIONING PUMP Feb. 9, 1960 Filed Jan. 28, 1955 I 5 Sheets-Sheet 4 ATTORNEYS Feb. 9, 1960 Filed Jan. 28, 1955 J. X. HOGAN FLUID PROPORTIONING PUMP 5 Sheets-Sheet 5 INVENTOR ATTORNEXB' United States Patent FLUID PROPORTIONING PUMP John X. Hogan, Washington, D.C. I

Application January 28, 1955, Serial No. 484,697

20 Claims. (Cl. 103-2) This invention relates to vane type pumps and more particularly relates to a vane type pump which is peculiarly adapted to be operated as a fluid driven proportioner.

Proportioners, particularly those used in producing foam for fire fighting, have for the most part consisted of a hydraulic motor actuated by the primary fluid and driving a separate vane type pump to feed the secondary fluid into the primary fluid at either the inlet or outlet of the hydraulic motor. Such an arrangement is shown in the patent to Granberg No. 2,567,997. While such units have proven generally satisfactory, they necessitate separate motor and pump assemblies and consequently cannot be constructed in a very compact form as is desired for certain marine and naval insallations. The majority of mixing pumps heretofore in use for mixing two or more fluids in one casing have generally not been adapted for use with inelastic fluids and, those that have been so adapted to do not provide a sufliciently eflective seal between the various ports to produce a high vacuum suction for the secondary fluid. To my knowledge, none of the previously available proportioner pumps have been adapted for use as a combined fluid motor and proportioner.

According to the present invention there is provided a vane type pump which, according to one embodiment of the invention, may be utilized as a combined fluid motor and proportioner pump to mix two fluids which may be inelastic while producing a high vacuum suction for the secondary fluid. Where the pump is utilized in this combined capacity it is constructed in a completely enclosed manner, so that there is no exposed shafting or bearings, there are no apertures to admit dust, dirt or abrasive materials and there is no problem of sealing at shaft bearings. The bearing for the rotor is centrally located so as to minimize bearing and pump wear. The fluid pressure drop through the unit is small and provision may be made for adjustment ofthe proportioning ratio.

According to another embodiment of the invention the vane type pump may be power driven by a separate unit to act either as a proportioner or as a vacuum pump. In the former instance the operation is similar to the opera- V tion of the combination fluid motor and proportioner and a central enclosed bearing is utilized along with a single shaft and a single alignment hearing which need not be sealed from the fluid in the pump. Adjustability may be provided as in the combined embodiment and suction may be applied to both the primary and secondary fluids. Where the unit is utilized as a vacuum pump a unique method of vane lubrication is provided to insure long life and the production of a high vacuum.

It is accordingly a primary object of the present invention to provide avane type pump capable of operation either as a combined fluid motor and proportioner or as an externally driven proportioner or vacuum pump.

It is another object of the present invention to provide a vane type pump which is capable of operation either as a combined fluid motor and proportioner or as an externally driven proportioner or vacuum pump in which the rotor is mounted upon a centrally located bearing.

It is a further object of the present invention to pro vide a combined fluid motor and proportioner pump of the vane type which produces a low pressure drop in the primary fluid actuating the motor.

It is another object of the present invention to provide a combined fluid motor and proportioner pump which may be produced as a single unitary completely enclosed unit.

It is another object of the present invention to provide a vane type proportioner pump which may operate either as an externally driven pump or as a combined fluid motor and proportioner pump wherein both fluids being proportioned may be inelastic'fluids.

It is another object of the present invention to provide a vane type proportioner pump which needs no priming and which is capable of producing a high vacuum.

It is another object of the present invention to provide a vane type proportioner pump which may be operated either as an externally driven unit or as a combined fluid motor and proportioner pump wherein internal liners are provided to give the unit a long life.

It is another object of the present invention to pro vide a vane type proportioner pump which may beoperated either as an externally driven unit or as a combined fluid motor and proportioner pump wherein the ratio between fluids may be adjusted.

It is another object of the present invention to provide an externalily driven vacuum pump having a rotor mounted on a centrally located bearing and having novel provision for vane lubrication.

It is a further object of the present invention to provide a vane type proportioner pump which may be utilized either as an externally driven proportioner pump or as a combined fluid motor and proportioner pump which utlizes a pair of internal liners one of which is movable to provide for adjustment of the proportioning ratio.

It is another object of the present invention to provide a vane type pump with an internal circuit sealed and segregated from the main inlet and outlet ports.

Further objects and advantages of the invention will become apparent upon reference to the following specie fication and claims and the appended drawings wherein:

Figure 1 is an elevational view of a pump constructed according to one embodiment of this invention with the cover plate removed;

Figure 2 is a vertical section of the pump shown in Figure 1 taken along the line 22 in Figure 1; I

Figure 3 is a vertical section of the pump shown in Figure 1 taken along the line 33 in Figure 1 and having the rotor removed; Figure 4 is a plan view of the cover plate with the outline of the liner cam surfaces, rotor and casing shown Figure 9 is a fragmentary vertical section of a pump showing another form of bearing arrangement.

Referring more particularly to Figures 1, 2 and 3 of the drawing, there is shown a combination fluid motor and adjustable ratio proportioner 10, comprising a casing 12 carried by a standard 14 and base 16. A hollow stud shaft 18 having a shoulder 20 is integrally attached to the standard 14 and defines therewith a central bore 22. The stud shaft 18 is threaded at its outer end at 24 and has a needle or roller bearing 26 mountedthereon and held in engagement with the shoulder 20 by means of a lock nut 28. A lubrication port 30 is provided in the shaft 18 and a cap 32 having a plug 34 and atmospheric vent 36 is screw threadedly mounted in the bore 22 to provide lubrication for the bearing.

Arotor 38 is rotatably mounted on the bearing 26 and is provided with a pair of shallow counterbores 40 and 42 which define shoulders 44 and 46. A lubricant seal of any suitable type is provided about the inner end of the shaft 18 and may, for instance, consist of a resilient ring 50, of J-shaped cross section, secured to the shoulder 46 by means of screws 52 and urged into sealing the fingers 88, 90 and 92 of the adjustable liner 80. A

engagement with the shaft 18 by means of a garter spring 54. The other end of the shaft is sealed by means of a seal plate 56, which is secured on a shoulder 58 of the rotor 38 by means of screws 60. The atmospheric vent 36 in theplug .32 prevents the build-up of excessive lubricant pressures, while the seals'50 and 56 prevent lubricant from entering the proportioner chambers and also prevent the fluid flowing through the pump from entering the bearing structure. The rotor 38 is provided with at least eightradial slots 62in which a plurality of vanes 64 are mounted for reciprocation.

A generally arcuate fixed liner 66 having a cam surface 67 for guiding the vanes .64, is mounted in the lower portion of the casing 12 and is keyed thereto by means of a key 68 and positioning spacer 70 received in a keyway 72 inlthe bottom of the casing 12. The fixed liner 66 extends upwardly to the right of the rotor 38 to a knife edge 74 (Figure 1), and extends upwardly to the left of the rotor to terminate in a pair of outer legs 76 and 78 (Figure 3). A generally arcuate adjustable liner 80 having a cam surface 81 and having a downwardly extending leg 82, is slidably mounted in the upper portion of the casing 12 with the leg 82 received in an off-set 84 in the right wall 86 of the casing 12. The adjustable liner 80 is slotted to form a plurality of fingers 88, 90

and 92 (Figure 3), which extend downwardly around the upper left quadrant of the rotor 38 and bear against the inner surface of the left side wall 94 of the easing 12. r

An adjusting arm 96 extends upwardly from the uppermost portion of the adjustable liner 80 through an aperture in the top of the casing 12 and terminates in a pointer 98 adjacent a scale 100-mounted on the top of the casing. One side of the arm 96 is provided with rack teeth 102 and these engage with the teeth 104 of a gear 106 mounted on a shaft 108. The shaft 108 is journalled in a support member 110 and is rotated by means of a hand wheel 112 which carries a lock nut 114. By .rotation of the handle 112, the adjustable liner.80 is moved vertically in the casing 12, with its position being indicated upon the scale 100.

The legs 76 and 78 of the fixed liner 66 and the fingers 88, 90 and 92 of the adjustable liner 80 interleave and overlap and have inner contours which provide a smooth transition and give a smooth and continuous cam surface for directing the vanes. 64 pass from the cam surface 81 of the adjustable liner 80 to the cam surface 67 of fixed liner 66 without .any abrupt shock as would occur with a butt type joint. This results in long vane life independent of position or the frequencyof adjustment of adjustable liner 80. I

An inlet fitting 114 having an inlet passage .116 is provided in the lower left quadrant of the casing 12, and this inlet passage 116 communicates with a series of slots 1'18, 120 and 122 (Figure 3), in the fixed liner 66. .An outlet passage 124 is provided in the upper left quadrant of the casing .12 communicating with the spaces between That is to say, the vanes secondary fluid fitting 126 is fastened to the standard 14 by means. of bolts 128 and provides communication with a secondary fluid inlet passage 130 in the upper right quadrant of the proportioner.

A cover pate 132 closes the casing 12 and is secured.

thereto by means of a plurality of bolts 134. As is best seen in Figure 4, the cover plate 132 is providedwith three arcuate surface passages 134, 136 and 138 which provide the proper operating pressures in the spaces 140 in the slots 62 behind the vanes 64. The surface passage 136 is connected bymeans of a passage 142 .to the inlet section of the proportioner, while the arcuate surface passage-134 is connected by means of a passage 144 to the outlet section.

The arcuate passage 138 provides communication with the space behind the vanes during the time that they move outwardly in traversing the expansion chamber.

Sluggish vane action or vane leakage inthis area greatly reduces the seal which isolates the secondaryfluid inlet zone and it is a feature of the invention that an effective means is provided to insure proper vane. following and adequate seal maintenence. To this end the arcuate surface passage 148 is provided in this expansion area at the outer periphery of the space between the stator. and rotor and is connectedthrough passage 146 to passage 138. As the primary fluid moves through the expansion zone it is held against the stator surfacehy centrifugal force and tends to retain a uniform depth. This creates a void adjacent the rotor and, with the effective sealing of the vanes and liquid, creates a near perfect vacuum for drawing secondary fluid into the expansion zone. Thesecondary inlet 130 islocatedbpposite this void and is similarly shaped.

The peripheral location of the passage 148 permits.

. utilization of the high kinetic energy of the fast moving i by the angle-A, comprises a segment of a circle having a t peripheral fluid and provides an effective force for rapidly forcing the vanes out against the stator cam surface.

In addition to harnessing the kinetic energy of the peripheral fluid, an increased centrifugal force is provided during the critical expansion period. While all of the vanes are forced outward by centrifugal force, the substantially complete floating of the vanes in the fluids being pumped markedly reduces this force in comparison to that attainable in air. However, during starting of the pump and before the secondary fluid is substantially filling the void createdin the expansion zone, a

portion of the vanes passing this point are enclosed by air and are subjected to a centrifugal force markedly greater than the completely, submerged vanes, thereby providing the desired seal for the critical expansion zone.

Referring to the dotted outlines of the cam surfaces of the fixed and. adjustable liners 66 and and the surface of rotor 38 in Figure 4, the cam surface 67 of the:

fixed liner .66, over the lower left quadrant, as indicated center at the longitudinal axis of the stud shaft 18. The cam surface 81 of thefadjustable liner 80, over the segment B, generally in the upper left .quadrantjas seen in Figure 4, also comprises a segment of a circle having a center on the longitudinal axis of the shaft 16, butlarger r in diameter than the circle which defines cam surface 67 her for drawing secondary fluidinto the pump through the secondary fl'uidinlet 130. Between theright end of segment Band the intersection .ofuthe rotor 38 with a horizontal center line, the surface of adjustable liner .80

curves smoothly to contact the rotor 38 onthe. horizontal center line as seen in .the upper. right quadrant in ,Figure 4 to provi e a gradual and smooth discharge-1 fi u arly the lower right quadrant cam surface 67 follows a smooth curve from the right end of the segment A to the surface of the rotor at the horizontal center line to provide a gradual and smooth intake.

The cover plate 132 is also provided with'a vertical surface passage 158 which connects the space 160 above the adjustable liner 80 to the outlet 124, so as to allow easy movement of the adjustable liner and to insure that this space is filled at all times with the fluid being handled. Similarly a vertical surface passage 162 is provided connecting the space 160 above the adjustable liner 80 with the off-set 84 of the casing 12, so as to permit free liquid ingress and egress to the space created here when the liner is moved upwardly.

The slots between fingers 88, 90 and 92 depending from adjustable liner 80 in Figure 1, define arcuate floors or channel bottoms shown by a dashed line at 152. In the adjustable ratio pump shown in Figure 1, these floors or channel bottoms are so shaped as to provide an annular chamber of such a volume as to prevent compression of the fluid beyond the vertical center line of the pump. The discharge zone thus commences at the vertical center-line of the pump and the cross sectional area of the annular chamber is preferably designed to be substantially constant from the vertical center line to the dischargeopening when the adjustable liner 80 is in its uppermost position. This construction provides a zero compression flow in this area over the entire operating range of the proportioner as isdiscussed presently in further detail.

Operation of the proportioner is as follows: Fluid under pressure is admitted through inlet fitting 114 into inlet passage 116 whereupon it passes through slots 118, 120 and 122 to enter the annular space between the cam surface 67 of fixed liner 66 and rotor 38. This fluid causes the rotor 38 to rotate in a counterclockwise direction and undergoes neither expansion nor compression in the lower right quadrant as seen in Figure 1. At

the knife edge 74 on the fixed liner 66, the annular space between the rotor 38 and cam surface 81 of adjustable liner 80 becomes increasingly enlarged so that a vacuum is created and fluid is drawn in through the secondary fluid fitting 126 and passage 130. It will be noted that there are at all times at least two vanes between this suction portion of the pump and either the inlet and outlet zones, and that all spaces therebetween are completely filled with fluid. In addition an amplified vane sealing pressure is provided by peripheral passage 138 so that an extremely high vacuum is produced. As the fluid moves past the expansion chamber adjacent the secondary inlet passage 130 to the vertical center line of the proportioner, it passes through a true annular space between the rotor and cam surface 81 and undergoes neither compression nor expansion so long as the adjustable liner is set at its basic design position (Figure 1). From this center line position the liquid enters the discharge zone and is discharged through the discharge opening 124.

' 'Referring to Figure 6 there is shown a diagrammatic representation of the effect of moving the adjustable liner :80. The position of the adjustable liner at its basic design position, corresponding to Figure 1, is shown in dotted lines at 154. Under these conditions expansion occurs through the are C, as explained in connection with Figure 1, and neither compression nor expansion takes place through .the following arcD. When the adjustable liner 80 is moved upwardly, as 'tothe position shown in solid lines at 156, the shape of the annular space between the rotor and liner is varied so that now expansion occurs throughout the are E and compression-would tend to occur through the small arc F were it not for the fact that the slots between the fingers 88, 90 and 92 allow discharge to commenceat the vertical center line. This construction is of the utmost importance where inelastic fluids are handled. since any. substantial compression on 6 the discharge side of the vertical 'center line would render the pump inoperative for any practical purpose.'

Further reference to Figure 6 will show that the annular space in the upper right quadrant, exclusively of are C, is truly annular at the lowermost setting of the adjustable liner 80. That is, the cam surface 81 is concentric with the rotor 38 over this arc at such a setting. When the adjustable liner is moved upward this concentricity is destroyed and the annular chamber progressively expands to the vertical center line. Confined expansion in this area may be eliminated by extending the passage 148 beyond the basic design expansion zone, which is generally coterminous with the secondary inlet 130, to satisfy the expansion from fluid in the basic ex, pansion zone. This renders the pump capable of operating over a large range of ratio variations but tends to reduce the effectiveness of the seal between the-secondary inlet or expansion zone and the discharge section of th pump. Thus as a practical matter the range of adjustability is limited by the amount of vacuum desired at the secondary inlet and generally speaking is only sufficient to correct variations from the basic or design ratio caused by changes in temperature and viscosity in the fluids being pumped.

Practical manufacturing tolerances make a perfect vane to stator seal impossible in any given instance and thus some slight theoretical compression may be tolerated immediately prior to entering the discharge area. By utilizing a large number of vanes and relying on leakage to relieve the compression in one or two intervane spaces prior to discharge it is possible to obtain a usable range of adjustability while still maintaining an efiective seal between the discharge and expansion areas.

While perfect sealing between any given vane and its stator is impossible it is a feature of this invention that near perfect seals are provided by utilizing the seal of several fluid filled intervane spaces between the expansion area and both the primary inlet and the outlet. At the basic design ratio the number of such seals is limited only by practical considerations of rotor size and consequently an almost perfectly sealed expansion area can be attained. Thus while a minimum of eight vanes is contemplated by this invention an unlimited additional number may be used.

In addition to the proportioner shown in Figures 1 through 6 which is capable of corrective adjustment, there is also shown in Figure 5, a proportioner constructed according to another embodiment of the invention wherein adjustable proportioning ratios are possible through the use of diiferent liners in the proportioner casing. Thus referring to Figure 5 there is shown a casing 170, housing a rotor 172 having radial slots 174 and vanes 176 mounted therein. The casing is mounted on a standard 178 and base 180 and is provided with an inlet fitting 182 having an inlet passage 184 and an outlet passage 186.

A lower liner 188, similar to the fixed liner 66 in Figure 1 and having a key 190, is mounted in the lower half of the casing 170 and positioned by, means of a key spacer 192 in the key way 194. An upper liner 196 is mounted in the upper half of the casing 170 and is positioned therein by means of a key 198 and key spacer 200.

In this embodiment of the invention the segment G of the, lower liner 188 comprises a segment of a circle centered on the longitudinal axis of the rotor as in the proportioner of Figure 1. Similarly the segment H is a segment of a circle centered on the longitudinal axis of the rotor and of a diameter larger than the diameter of the segment G. Between the segments G and H the inner surface of the upper liner 196 follows an increasing radius path to join these two segments with a smooth curve at the secondary inlet portionof the proportioner. Since the upper liner 196 of this proportioner is not adapted to be moved, the problem of compression and aces-give expansion in the 'annular space across the-vertical center line is not presented and proportioner discharge need not commence at the vertical center line. Accordingly the floors 202 of the slots between the fingers 204 and 205 connect the end of the segment H to the discharge opening- 186 commencing at the end of segment H. The surface passage 148 in the cover plate does not extend beyond the expansion zone between segments G and H.

When it is desired to change proportioning ratios the cover plate is detached and the upper liner 196 removed and replaced with a liner having a different ratio between the radii of the segments G and H. Since the segment H in all such liners is a circle centered on the axis of the rotor, there is no compression and expansion on opposite sides of the vertical center line and propor tioner discharge commences at the end of the segment H rather than at the vertical center line of the unit thereby providing additional sealing of the expansion area.

In addition to the foregoing pumps having two rcmovable liner sections, it will be apparent to those skilled in the art that unitary liners may be utilized and that pumps'may be provided in which the annular chamber around the rotor is defined by the inner surface of the casing itself without the use of separate liners. Such a unit may operate as a fixed ratio proportioner and can be manufactured at an extremely low cost. In most instances, however, it is desirable to provide removable liners, sincethese may be replaced after wear has occurred to materially increase the life of the pump unit;

The proportioners shown in Figures 1 and,5 may be manufactured in a compact form and, because no external source of motive power is needed, are absolutely portable. The fluid pressure drop through the units is very low, the proportioner needs no priming, and produces a very high suction. The single centered bearing minimizes wear and the entire unit is enclosed so that it is unnecessary to provide external seals which might influence the vacuum produced. The secondary inlet zone is relatively completely isolated from both the primary inlet and the outlet and it is possible to provide two or more intervane sealing spaces. on either side of the expansion zone. Amplified forces are provided for actuating the vanes in the critical expansion area through the use of a completely segregated and isolated internal fluid circuit. The pump cover plate is readily removable and provides access to all internal pump parts without the necessity of dismantling fluid or drive connections. Rotor, vane or liner replacement is thus a simple andrapid operation.

, While the units shown in Figures 1 through 7 are fluid driven, there are instances, as for instance, where the primary fluid is not supplied under pressure, where it is desirable to drive the unit from an external source of power. Such a pump is shown in Figure 7. This unit comprises an adjustable proportioner, such as shown in Figure 1, and consists of a standard 210 supporting an integral casing 212 and having a hollow stub shaft 214- carried centrally thereof. The shaft 214 has a shoulder 216 against which a bearing 2218 is positioned. A rotor 220 is carried upon the bearing 216 and is provided with slots 222 and vanes 224. A fixed liner 226 is mounted in the lower part of the casing 212 and an adjustable liner 228 is mounted in the upper part of the casing and is adjusted by means of the mechanism 230 which is similar to that described in detail. in connection with the proportioner shown in Figure l. A cover plate 232 is secured to the casing 212 by means of bolts 234. A shaft 236 passes through the bore 238 in the stub shaft 214 and is drivingly secured to the rotor 220 by means of a drive plate 240 and screws 242. A garter spring type seal 244 is provided at the inner edge of the bearing 218 in the same. manner as in Figure l.

A flanged housing 246 is secured to the "standard 210 externally of the proportioner by means of bolts 248 and a tapered bearing 250 mounted therein against asheet der-.252. A bailiff-254 is also carrid by the shaft 236 andis secured in position against the bearing '25!) by means of a closure plate 256, which is held in position by screws 258.

This unit operates in a manner similar to the proportioner or Figure 1 and may be utilized whereithe primary fluid: cannot be supplied under pressure. The rotor is carried upon a single centrally located bearing, so as to minimize bearing wear, as with the unit of Figure 1, and the external bearing 250 serves as an alignment and positioning bearing- By means of this arrangement the shaft 236 is relieved of all radial loading including rotor weight and pressure thrustloading. 0nly'a singleseal 244 is necessary and the motor and propdrtioner maybe combined into a single integral unit as shown in Figure 8, wherein a motor 260 is flange mounted to a proportioner 262 to form a compactportable unit. Such a unit may dispense with the. external alignment bearing 250 where the motor is provided with bearings suitable forhandling the axial thrust It will be obv'iousthat the adjustable proportioner unit of Figure 7 may be supplied as a fixed unit, eliminating the adjustment arrangement 230, and also eliminating the, separate liners if so desired.

Referring to Figure 9 of the drawings there is shown still another methodof providing. hearings in a driven unit. This, unit comprises a pump casing shown fragmentarily. at 270, having a hollow stub shaft 272 at tached thereto as in thegpreceding embodiments. A drive shaft 274 having a shoulder 276 passes through the stub shaft and is drivingly connected to the rotor 276 by means of a plate 278 and screws 280. A double alignment and thrust bearing 282 is seated. against the shaft shoulder 276 and is supported in a :flanged housing 284 in a manner simila'rto that shown in Figure 7.

In addition to using the driven units as proportioners, it is also possible to use them as highly efficient vacuum pumps by providing, a verysmall flow of primary fluid sufiicient .onlyto lubricate the ,vanesof the pump. With this type of unit. the lower liner mayhave its c'am sui'iface so shaped as. to pro ide a very small annular space between the rotor, and the liner and, where pumping gases, the liquid thus introduced, into the gas emanates from the pump outlet as a fine spray or vapor. a liquid is being pumped through the secondary inlet, the lubricant may be supplied by bleeding a small amount of the liquid fromthe. liquid supplyvinto the primary inlet. It will be apparent from the foregoing that according to this inventionthere is provided. av completely sealed proportioner which may be driven by the primary fluid being proportioned. The pressure drop through the unit is extremely small and a' high vacuum or suction is created. A well sealed secondary inlet is provided and a segregated pump circuit isutilized for providing adequate vane to stator scaling in the critical expansion area'.

The unit may be provided in a completely and continuous- 1y adjustable form,- in a step adjustable form and also in a non-adjustable fixed ratio form. The pump may be externally driven if desired and, in such a case, it may be utilized as a proportioner or as a vacuum pump. in all instances the rotor is supported on a single centrally located bearing so as to minimize bearing wear and the entire unit is of "simple and rugged construction.

The invention may be embodied in other specific terms without departing from the spirit onessential character? istics thereof. The present embodiments are therefore to be considered in :all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to bit-secured by United States Letters Patent; is

V 1. A fluid. co n" Where i one side and forming an'open chamber, a stub" shaft fixedly attached to said casing and extending thereinto, bearing means mounted on said shaft substantially at the lateral center of said chamber, a rotor havingradial slots rotatably mounted on said bearing means, a'plurality of vanes slidably mounted in said rotor slots and at all times engaging the peripheral wall of said chamber, said peripheral wall forming a cam surface for said vanes generally eccentric with respect to said rotor and contacting said rotor at one position, a cover plate mounted on said casing to completely enclose said proportioner, a first inlet in said casing adjacent said contact position, an outlet in said casing spaced from-said first inlet, said peripheral wall receding from said rotor between said first inlet and said outlet and being'spaced from said rotor a greater distance at said outlet than at said first inlet, said peripheral wall having a first portion thereof between said first and second inlets concentric with said rotor and a second portion thereof between said second inlet and said outlet concentric with said rotor, said peripheral wall receding from said rotor between said concentric wall portions, and a second inlet in the side wall of said casing at the point where said peripheral wall recedes from said rotor, said second inlet being spaced radially inward from said peripheral wall.

2. A proportioner comprising a'casing defining a chamber, a rotor having radial slots mounted to rotate in said chamber, a plurality of vanes slidably'mounted in said rotor slots, the peripheral wall of said chamber forming a cam surface for said vanes eccentric with respectto said rotor and contacting said rotor atone position, a first inlet in said casing adjacent said contact position, an outlet in said casingspaced from said first inlet, said peripheral wall receding f om said rotor between said first inlet and said outlet and being spaced from said rotor a greater distance at said outlet than at said first inlet, and a se ond inlet in said casing at the point where said peripheral wall recedes from said rotor, first conduit means connecting said inlet to spaces in said slots behind vanes situated between said inlet and the point where said peripheral wall recedes from said rotor, second conduit means connecting the space where said peripheral wall recedes from said rotor to spaces in said slots behind vanes situated in said space where said peripheral wall recedes from said rotor, and third conduit means connecting said outlet to spaces in said slots behind vanes situated between the point where said peripheral wall ceases to recede from said rotor and said outlet, said first, second and third conduit means being isolated from one another.

3. A proportioner as set out in claim 2 wherein said second conduit is connected to said space where said peripheral wall recedes from said rotor at a position spaced radially outwardly from the peripheral surface of said rotor.

4. A proportioner as set out in claim 2 wherein the spaces in said slots behind said vanes are isolated except where connected to said conduit means.

5. A proportioner as set out in claim 2 wherein said conduit means are in side walls of said casing.

6. A proportioner as set out in claim 4 wherein said casing comprises a first portion having a side wall and a peripheral portion and forming van open chamber, the inner surface of said peripheral portion forming said peripheral wall, a stub shaft fixedly attached to said side wall of said first portion and extending into said chamber, bearing means mounted on said shaft centrally of said chamber, said rotor being mounted on said bearing means, and a plate attached to said first portion and forming a second side wall to close said open chamber.

7. A proportioner as set out in claim 5 wherein said conduits are in said plate.

8. A proportioner as set out in claim 2 wherein said second inlet is spaced radially inward from said peripheral wall and said pump contains suflicient vanes so that at least two adjacent vanes at all times maintaiir an isolated column of fluid between said first inlet and the position where said peripheral wall recedes from said rotor and at least two additional adjacent vanes at all times maintain an isolated column of fiuid'between said second inlet and said outlet. g

9. A proportioner comprising a casing open at one side and forming an open chamber having a side wall and a peripheral wall, a hollow stub shaft fixedly attached to said side wall and extending into said chamber, hearing means mounted on said shaft centrally of said chamber, a rotor having radial slots rotatably mounted on said bearing means, a plurality of vanes slidably mounted in said rotor slots, the peripheral wall of said chamber forming a cam surface for said vanes eccentric with respect to said rotor and contacting said rotor at one position, a cover plate mounted on said casing to enclose said chamber, a first inlet in said casing adjacent said contact position, an outlet in said casing adjacent said contact position and ,on the other side of said rotor from said first inlet, said peripheral wall receding from said rotor between said first inlet and said outlet and being spaced from said rotor a greater distance at said outlet than at said first inlet, a second inlet in the side wall of said casing at the point where said peripheral wall recedes from said rotor, said second inlet being spaced radially inward from said peripheral wall and being located adjacentthe peripheral surface of said rotor, said rotor containing at least eight vanes whereby at least two adjacent vanes. at all times maintain an isolated column of fiuid between said first inlet and the position where said peripheral wall recedes from said rotor and at least two additional adjacent vanes at all times maintain an isolated column of fluid between said second inletand said outlet, first conduit means in said plate connecting said inlet to spaces in said slots behind vanes situated between said inlet and the point where said peripheral wall recedes from said rotor, second conduit means in said plate connecting the space where said peripheral wall recedes from said rotor to spaces in said slots behind vanes situated in said space, one end of said second conduit means terminating in said space adjacent said peripheral wall, and, third conduit means in said plate connecting said outlet to spaces in said slots behind vanes situated between the point where said peripheral wall ceases to recede from said rotor and the point of contact between the rotor and the casing, said first, second and thiri conduit means being isolated from one another.

10. A proportioner comprising a casing defining a chamber, a rotor having radial slots mounted to rotate in said chamber, a plurality of vanes slidably mounted in said rotor slots, the peripheral wall of said chamber forming a cam surface for said vanes generally eccentric with respect to said rotor and contacting said rotor at one position, a first inlet in said casing adjacent said contact position, an outlet in said casing spaced from said first inlet, said peripheral wall receding from said rotor between said first inlet and said outlet and being spaced from said rotor a greater distance at said outlet than at said first inlet, and a second inlet in the sidewall of said casing at the 1- Jllli vrhere said peripheral wall recedes from said rotor, said second inlet being spaced radially inward from said peripheral wall, said rotor having a sufficient number of vanes mounted therein, so that at least two adjacent vanes at all times maintain an isolated column of fiuid between said first inlet and the position where said peripheral wall recedes from said rotor and at least two additional adjacent vanes at all times maintain an isolated column of fluid between said second inlet and said outlet, said casing including a lower liner ele ment forming the peripheral wall of the lower portion of said chamber, and an upper liner element forming the peripheral wall of the upper portion of said chamber, one of said liner elements being adjustable.

11 A x t t n r cu si cas .dfisir w h mbsn ater hav g adia s a m nted. qratata ins idra bcr a p u ali o e idab Wante n Sa d rot s o t sr her W l of a d ch b iq mia a a Surface .f saisi an ge erall e entri with respect to said rotor and contactingsaid rotor at one positioin a firstinlet in said casing adjacent said contact position, an outlet in said casing spaced from isai di first inlet, said peripheral wall receding fromsaidrotor between said first inlet and saidoutlet and being spaced from said rotor a greater distance at said outlet than at said first inlet,'anda second inlet in the sidewallto fsaid casing at the point where said peripheral wall recedes frorn said rotor, said second inlet being spaced radially inward from said peripheral wall, said rotor having a V sufiicient number of-vanes mounted therein, so that at ripheral wall recedes from (said rotor; and means forreturning all of saidwithdrawn fiuid'to said outlet,

12, A proportioner comprising a casing defining ra chamber,"a rotor having radial slots'mountedto rotate in said chamber, a plurality of vanes slidably mounted in said rotor slots, the peripheral wall of said chamber forming 'a scam surface for saidvanes generally eccentric withlrespject to said rotor and contactingsaid rotor at one position, va first inlet in said casing adjacent said contact position, an outlet in saidcasing spaced from saidfirst inlet, and a second inlet in the side wall of said casing between said first inlet and outlet, said peripheral wall, having a first portion thereof adjacent said first inlet, concentric-with said rotor and a second portion thereof spaced from said first concentric portion andadjacent said outlet concentric with said rotor, said peripheral wall receding from said rotor between said concentric wall portions at the position of said second inlet so that said peripheral wall is spaced from said rotor a greater distance at said outlet than at said first inlet, said second inlet being spaced radially inward from said peripheral wall, said concentric portions ex f 1-i opq qne s set Out in esinsaataa wifi i eri al we" l a t ddifiqna n s at a tim a ma a F9 is lat s! co umn 10 uid int i nd s entr a a pp iq d fr m. e sl ew b twa n aid rrowr a P r h ra 3 W1 3? sa q pbri l etal w ll re ede fr m a mm:-

1 14,, A: proportioner as set out in claim 13 including rneans .ior metering :the fluid withdrawni froni said :space. liaaq ns a se ut cla m: 14 w sr z said" behind saidivanesy a d u w t d watlitwsh a ondui w ch p c in i 'i 'r wi hd aw n a e a? s id li ml l wa er qi id mtara,

1 p porti aer as w 9st sma l? here n a a d' e qnd n t is ad a P9 .phaa wim of s d rot 1 A ja rcrti i uti l a m 112, inq dias t a ub shaf fixedly atta to a d lea n a d tendn l 'ih Fs n o aidram b n im arte to o t o on d haf onv bq q me ass sted vbsmm a the axi nter Pl ne aid am A w tio s a tqut n, Q aim- 9 h rein said stubisha ft is hollow, and including a drive shaft received in said stub shaftyand drivingly ,connected to Referenees file offthis patent UNITED STATES PIYFENTS 1304504 Gilbert; 'May 12, 1931 1,833,275 Burrneister Nov. 24, 1931 2325,803 Smith Dec. 24, 1940 2,238,786 Worman 4. Apr. '15, 1941 agsazn Sullivan--; ;s Apr. 21, 1942' "FOREIGN PATENTS Grea Britain 8, 1934 ta it i f fitii r rt qns't er qits at s ttwbr edjer st sa a ll mc maima s fi st i q s 0. am t tflsid in ari fi st s nl riqwel Part sa nd a a j w rt aar s t win-s m 12 i i in ,a secondary flilid cirenit providing for withdrawal of m r is ac'wni lish d n th s ces i skit a a n i m rfl dtmm th P? t st! id remand Per he al l w er 

